With a view toward executing transmission of information between a cellular phone and a digital network device, or the like, a memory card like a multimedia card has been proposed which has implemented a reduction in size and weight and simplification of an interface. As described in, for example, the Interface (December issue in 1999) issued by CQ Publishing Co., Ltd., a multimedia card has seven connector terminals as external interface terminals and adopts a serial interface. This is capable of reducing a load on a host system as compared with an ATA interface adopted by a PC card or hard disk and is available even for a simpler system. Further, the same reference has also described that an SD card has been proposed as an upper compatible memory card of the multimedia card.
The present inventors have discussed a function expansion of a storage-system IC card such as a multimedia card or the like. Thus, the present inventors have previously filed the invention wherein extension terminals are provided while compatibility is being maintained with respect to a standardized terminal array of a multimedia card or the like, thereby enabling a function expansion such as an increase in the number of data bits (Unexamined patent application No. 2000-18030). Further, the present inventors have carried out discussions directed toward the implementation of a multibank or multifunction using such extension terminals. In a GSM (Group Special Mobile) mobile communication system or the like using an SIM (Subscriber Identity Module) of an IC card, for example, an SIM card has a single chip microcomputer or the like, which stores subscriber information and account information or the like necessary for subscriber acknowledgement and management for security and realizes communication protocols, and which builds therein a nonvolatile memory such as a flash memory, for example. When one attempts to apply a storage card such as a multimedia card to a cellular phone of such a GSM mobile communication system, an insertion slot for the storage card is required in addition to one for the SIM card. Thus, the present inventors have found that there is room for improvements in terms of space factors. Further, the present inventors have found that a difference in security level unavoidably occurs in memory information between the storage card and the SIM card and hence there is a necessity that the difference in security level is allowable as a difference upon the multifunction.
An object of the present invention is to provide an IC card capable of executing a function expansion such as a multibank or multifunction or the like while compatibility with a predetermined standard is being maintained with respect to a terminal array.
Another object of the present invention is to provide an IC card capable of expanding multifunctions different in security level.
The above, other objects and novel features of the present invention will become apparent from the following description of the present specification and the accompanying drawings.